Spinning spindle



June 8, 1954 T. w. MORRISON ET Al.

SPINNING SPINDLE 3 Shee'cs-Sheeil l Filed Feb. 8, 1952 June 8, 1954 T. w. MORRISON ET AL 2,680,659

SPINNING SPINDLE Filed Feb. 8, 1952 3 Sheets-SheetI 2 June 8, 1954 T. w. MORRISON ET A1. 2,680,659

SPINNING SPINDLE Filed Feb. 8, 1952 5 Sheets-Sheet 3 Patented June 8 1954 SPINNING SPINDLE Thomas Watson Morrison, Elkins Park, and Haakon Styr, Philadelphia, Pa., assignors. to SKF' Industries, Incorporated, Philadelphia, Pa., a corporation of Delaware Application February 8, 1952, Serial No. 270,714

26 Claims. l This application-is a continuation-in-part of our co-pending application, SerialNo. 219,703, now abandoned.

This invention relates to improvements vin textile spindles.

Following the tendency `in all modern production,- yarn and thread spinners have asked for higher and higher spindle speeds to 4increase the rate of production.. Higher speeds increase the eiect of unbalancein the bobbin and rotating spindle parts and in the winding ofthe bobbin. Unbalance in the windingseems unavoidable, and therefore it is necessary, in operating at higher speeds, to develop better means of damping the.`

vibrational movements. In the interest of producing cheaper yarn and thread, it becomes necessary, also, to reducepower consumption and manufacturing costs of the spindle,l simplification of construction aiding materially with thet latter.

An .obj ect of this invention is to provide a spinning blade mounted at the upper end of the base in a standardized ball bearing which actsV as a fulcrum for the 'precessional motion of the spindle, and at the lower end in a standardizedball bearing supported sofas to vpermit slight presessional movement damped by oil; and by frictional resistance.

Another object iste support the outer race of the lower bearing by axiallpressure between two springs, as distinguished from supporting it in ahousingr in the radial direction as in present practice.

Another object is to supporttheA outer race of the lower bearing ley-pressure Ibetweenrtwo washrace, thereby to provide a practical organization by which to regulate the damping effect of the spring pressures without imposingload on either bearing.

Still another object is toprovide-a spinning spindle assembly incorporating a novel system of control for the .normal precessional motion of the spindle, employing both fluidv and frictional damping as hereinafter more fullyA set forth, said system being independent of the specicfnature of the bearings in which the spindle blade is mounted, and affording smooth and substantially vibrationless spindle operationat relatively high speeds.

A further object is toprovide-a spindle assembly of the aforesaid characteristics wherein the blade'is mounted at'the upper end of the base in a roller bearing wherein-provision'is made for the oscillatory'precessional motions of" the blade.

A still further object. is to` provide a spindle assembly of the aforesaid characteristics Wherein the lower end of the blade is mounted in a step bearing with provision also for the oscillatory precessional motions of the blade,

Other objects will appear fromthe specification.

In the attacheddrawings:

Fig. 1 is a cross-sectional view in elevation of the 'spindle assembly;

Fig. 2 is an enlarged cross-sectional view of the lower end of the spindle;

Fig. 3 is a cross-sectional view in elevation of a spindle assembly illustrating a modicationwithin the scope of the invention;

Fig. 4 is an enlarged fragmentary cross-sectional view showing-the. details of structure of the assembly of Fig.' 3;

Fig. 5 is a cross-sectional view in elevation i1- lustrating a. further modification within the scope of the invention.

The embodiment of the invention shown in Fig. l comprises a bladevl, which carries a bobbin (not shown) and a whorl 2. The blade is mounted on two'ballbea'rings, anupper bearing 3, which is secured by its outer race between a screwed cover 4 and a shoulder 5 at the upper end of base 6, and anlowerV ball bearing T in the lower part of said base. The upper bearing here shown is a deep groove annular ball bearing which will accommodate without injury, an angular swing of the spindleaxis of about 10 minutes of arc, especially whenthe balls are fitted between races with'a very slight looseness. Obviously, a self-aligning bearing would'care for a longer swing. The lower-'bearing is a deep groove annular ball bearing whose outer race is supported in the axial direction-by two identical annular pieces 8, 3 each of 'which has a flange 9 fitting into the bore ofthe outer race. The outboard lfaces of these pieces form frictional conapex at the center of the upper bearing. thermore, the forces due to the variously offset onto the blade with a press nt. Adoes not touch the inside of the base and gets tact surfaces Ill, in the present instance of conical form, which match with like surfaces on the lower end of a sleeve II and on the upper surface of a lower washer I2. A considerable clearance i3 surrounds the outer race so that the lower bearing, contrary to previous practice, has no direct radial support. The lower piece il rests against the conical upper surface of the washer I2 which in turn rests on a spring Ill in the bottom of the base S. Upper spring presses sleeve l downwardly against piece 8, also presses upwardly against a flat ring held between the outer race IS of the upper bearing 3 and a shoulder 5 in the upper en@ of the base B.

The principal difficulty in operating spinning spindles comes from the unbalance in the rotating parts, which besides the spindle itself, include the yarn, the bobbin, the whorl, and the inner races of the ball bearings. Each of these will almost certainly have some imperfection which places its center of gravity to one side or the other of its axis. The resultant of all these displacements creates a centrifugal force during operation that tends to pull the top end of the spindle in the radial direction about the center of the upper bearing as a fulcrum. Since these rotating' parts considered as a single mass, act like a gyroscope, the above radial force causes it to precess, i. e. follow a conical path having its Furcenters of gravity, will cause vibration in the blade in addition to the precessional movement. It becomes necessary, therefore, to control these movements in order to accomplish au even and lsatisfactory winding on the bobbin and to avoid breakage of the material.

This invention achieves control by the novel method of mounting the lower bearing in a Swinging support damped at first by a small displacement of a quantity of oil I'l and subsequently by frictional resistance due to pregressively increasing compression of the two opposed springs, I4 and l5. Y

The upper deep groove ball bearing may be of e' standardized design and dimensions and hence obtainable at lowest cost. it goes on the blade with a press lit in its bore and into the base with a slip fit, which mounting accords with standard practice. The balls have small clearance in the races after mounting, to allow the blade to follow its conical path without cramping the balls and thereby adding a parasitic load which would unduly shorten the useful life of the bearings.

The lower deep groove ball bearing also may be I of standardized design and dimensions and goes Its outer race its radial support from the two springs acting through the sleeve II above, the washer l2 belo. and the two flanged pieces 8.

Observation will show that the upper spring i5 dimensioned to produce compression, exerts pressure up against the outer race of the upper bearing and down against the outer race of the lower bearing which in the absence of the lower spring, would transmit it through the balls to its inner race. The inner race grips the l wer end of the spindle tightly enough to take a considerable amount of axial load without slipping so that I5 whichv 4. would actto shorten the lives of the two bearings, corresponding to its amount. Since the useful life of anti-friction bearings decreases in inverse ratio to the cube of the load imposed, any relief of such a loading would greatly extend the durability of the spindle. This invention provides relief of such parasitic loading by lower spring Ill. When dimensioned for proper compression, the lower spring will press upwardly through the washer I2 and lower piece 8, against the underside of the outer race of the lower bearing and counteract as much as desired of the downward pressure of the upper spring I5.

Preferably, the weight of the yarn, the blade, and its attachments will rest principally on the upper bearing, in which case the direction of load through the balls will point downwardly as indicated by the upper solid arrows. Pressure of upper spring i5 would then load the lower bearing as indicated by lower solid arrows and take all looseness out of that bearing. The lower spring Id should exert sufficient force to nearly but not quite balance that of spring I 5, so as not to disturb the downward direction of the arrows.

The lower spring may exert greater pressure,

and thus move the outer race of the lower bearing far enough up against the upper spring to reverse the direction of loading through the balls on the lower bearing, to the upward direction as indicated by dash line arrows. The lower bearing would then assume a portion of the weight of the blade assembly, and have no looseness. Loading arrows would then point downwardly in the upper bearing and upwardly through the lower bearing.

The lower spring could exert still greater pressure which would compress the upper spring further and move the lower bearing enough higher to lift the entire weight of the spindle assembly. Preferably, it should also take the looseness out of the upper bearing and impose thereon a slight load in addition. Winding conditions may arise in which such an arrangement proves desirable.

Tests show smoother running of the spindle and less vibrational disturbance with both bearings carrying enough load at all times to remove all looseness therefrom and to impose a slight preload in addition. Such a preloaded condition can be maintained either with both sets of arrows pointing downwardly, both pointing upwardly, or with one set pointing upwardly and the other downwardly.

Clearly, the novel swinging support of the lower bearing provides possibility of wide variation in the pressure on the conical surfaces, because the springs react one another entirely through the outer race of the lower bearing, and the upper spring receives its support through the outer race of the upper bearing. rThe conical surfaces therefore can supply a high resistance to swinging without requiring the bearings to carry more than the weights of the rotating parts plus a slight preload. This resistance acts only if the end I8 of the sleeve Ii and edge l2 or" the washer I2, swing into contact with the inside surface of the base, Thus, the invention can supply any needed force tending to keep the blade in a centralized position without abnormally loading the bearings.

Because it can supply a large resistance to tilting caused by the pull of the tape in the position overhanging the two bearings, this organization permits use of a whorl much smaller in diameter than used in previous practice. Since the small whorl will require less linear speed for the same rotational speed, and also tend to produce-less centrifugal force from unbalancing. eifects. it cuts down windage losses of tape, whorl, and driving cylinders, and that saves power and vibrational disturbances. This feature constitutes an improvement over previousspindles which .must place the tape pull in line with the center ofthe upper bearing to minimize. load thereon and to relieve the `lower bearing of any load therefrom.

While turning, thelower end of the blade will pick up a small amount of oil by adhesion and carry it -by centrifugal force up its outwardly tapering-surface, until it reaches the inner race of the upper bearing which tightly ts the blade. The inner race then ings it violently outwardly against the bore of the ring whence some splashes into the bearing and the rest intothe reservoir. Any oil passing through the bearing Will-*be kept from escaping by the dinger action of the upper side of the inner race of the upper bearing. This arrangement not only lubricates the upper bearing but also keeps oil within the base and constitutes an improvement over previous spindles having rollers running directly on the blade or loose -ts in the upper bearing; both of these conditions would allow oil to pass through the bearing outside of the base and onto unenclosed parts. Eventually, such oil would reach and spoil the material.

In the embodiment ofthe invention illustrated in Figs. 3 and 4, the spindle structure is essentially the same as that illustrated in Figs. 1 and 2 and described above, with the exception, however, that means have been incorporated for aording additional oil damping. In this case, the blade 2l is mounted as before on two ball bearings, an upper bearing 22 and a lower bearing 23. The upper bearing 22V is of acharacter. that will accommodate without injury a substantial angular swing ofthe spindle axis. The Vlowerbearing 23 fis supported in the axial direction by two annular pieces 2t and 2t corresponding to the 'pieces 8, 8 of the previously described embodiment, and the conical outboard faces of the pieces 24 and 25 are engaged with the corresponding conical surfaces 25 and 2l', respectively, of a lower angular member or washer 2S and a sleeve 29, said sleevek seating upon the conical surface of the piece 25 and extending upwardly in the cylindrical base or housing Sii of the spindle structure. The washer 28 is supported by a spring 3l in the bottom of the base 3G, and the sleeve 2Q. is urged downwardly upon thepiece 25 by a second spring which is confined between the upper end of the sleeve and an out-turned ange body portion of the washer 28, which surface is normally flush with the outer cylindrical surface 2l of the piece 2d. Similarly, the outer cylindrical surface 33 of the piece 25, .which is ush with the surface 3? of the piece 24 and also with the outer cylindrical surface 3S of the outer race ring te of the lower bearing 23, is also normally flush with the outer surface 4| of the immediately adjoining portion of the sleeve 29. The surface 4! of the sleeve terminates in a shoulder42 which projects outwardly and terminates in the-'outer i cylindrical surface 43 of themain'portion ofthe sleeve. This outer cylindrical surface 43 is `normally spaced apart from the confronting inner surface of the'base 30 to an extent materially greater than the normal clearance space between the ange 35 of the washer 28 and the confronting inner surface of the said base. The outer cylindrical surface 44 of the sleeve 34 is also normally in spaced relation to the inner surface 45 of the sleeve 29.- It will be noted that the upper surface of the ange 33 of the sleeve 34 seats against the under side of a ring 2n corresponding to the ring 2i? of the previously described embodiment of the invention.

In the operation of this spindle, as the lower end of the bladeis displaced to the left, as viewed in Fig; 4, from its normal centered position, the iiange 35 of the washer 28 will almost immediately contact the adjoining, inner surface ofthe base Si?. Frictional resistance at the lower contact surface 2t and resistance due to displacement of oil from the space between the sleeve 2Q and the confronting'wall ofthe base' 3B will then damp the lateral motion of the blade until the corner of the sleeve 29 at the outer end of the shoulder e2 contacts the inner' surface of the base 30. In this initial damping'process the piece 24 moves with respect to the washer 28 on the surface 26, and the sleeve 2 9 will move bodily with thexpiece 25. After the sleeve 29 contacts the wall of the base at, and is thereby immobilized against further outward radial displacement, the subsequent continued movement of the blade 2l will cause the piece E5 to move with respectto the sleeve' 29 with resultant friction at the upper contact surface 2l, thereby further damping the movement of the blade. At this point, also the'sleeve`34 :ill begin to move with respect to the sleeve 29, thereby generating additional resistance due to displacement of the oil'from the space between the-sleeves. This additional oil damping continues until the lower corner 46 of the lower piece 24 Acomes in contact with the inner surface of the base 3d. Beyond this point no further extension of the angularmovement of the blade is permitted.

in damping devicesused Vto control the amplitude of the conical movement of spindles of the character involved in thepresent invention, the frictional 'drag 'between theaforedescribed conical or other contactsurfaces tends to'spasmodic action as' distinguished from the continuously smooth damping'action of the oil displaced from the space between the sleeve 2.! and the wall of the base.v Increase of pressure between the springs 3 i and 32' to obtain greater damping elfect will' increase the spasmodic tendency. This placesL a limit on springpressure as a damping medium; Decrease ofA spring pressure on the other hand, reduces spasmodic action and tends to smooth the damping elect.v

The structure illustrated in Figs. 3 and 4, and described above, introduces an additional period of oil damping which permits a corresponding reduction in the relatively undesirable frictonal damping, the latter reduction being eifected by reduction in the pressure of the springs 3i and 32 and materially improving the smoothness of the damping action as whole. The provision of the inner sleeve 3a affords an additional retardingforce which comesv into action in cases of relatively great imbalance orat higher speeds,

which greatly decreases or completely eliminates erratic vibration which tends to develop higherk speeds or under abnormal conditions.

The embodiment oi the inventionillustrated in Fig. 5, while employing the same general system of damping including both iiuid and sliding `friction, differs from the previously described embodiments in several important respects noted below. The blade l in this instance is mounted -in an upper anti-friction bearing 52 of the roller type, and at the bottom in a step bearing 53. The

r`latter bearing, which supports the Weight of the blade, is secured in the lower end of a sleeve 512' .which has a radial outturned flange at its upper end seating upon a shoulder 5E in the upper end of the base 5l of the spindle assembly. The sleeve 54 depends freely from the supporting shoulder 55 and normally has clearance at its .sides with the other elements of the assembly so `as to be free for lateral motion of an oscillatory nature as hereinafter described. As shown the fsleeve 54 terminates short of the bottom or" the base 5l.

The bearing 53 taires the form in the present -instancm of a cylindrical block having an inwardly tapered, conical stepped bore in which 'the correspondingly shaped lower end 59 of the blade 5l is seated. The bearing block is confined in the lower end of the sleeve 5d between a shoulder Si in the latter and the conical inturned lower extremity 52 of the sleeve. A slot 63 extends ydiagonally upward from the exposed bottom of the bearing block 53, and a port S4 establishes 2':- Ycommunication between the upper end of the end of an upturned cylindrical flange on a closure plug (il at the bottom of the base 5l. The sleeve $5 is forcibly held t0 this conical seat by pressure of a spring 68 which is coniined between the upper end of the sleeve and the underside of the collar 69 in the interior of the base 5l which forms the shoulder 56 previously referred to. It will be noted that the flange E@ is spaced inwardly from the side wall of base 51 and that normally a similar clearance will exist between the sleeve 55 and the said side wall of the base.

In the aoredescribed device, the bearing 52 will have suiiicient inherent looseness to afford the maximum permitted lateral displacements of the lower end of the blade and to permit ready insertion of the blade in its mount. The bearing 52 serves in effect as a fulcrum on which the blade may oscillate to the limited extent provided for by the clearances between the sleeves 5 and 65 and between the latter sleeve and the wall of the base. Initial lateral displacement of the lower end of the blade and of the lower end of the sleeve 54 is resisted by inertia of oil within ,the space between the sleeve Ell and sleeve 55 and the frictional resistance of the oil to displacement. When the lower end of the sleeve Sli has contacted the sleeve E5 further lateral displacement is resisted by the inertia and frictional resistance of the body of oil in the space surrounding the sleeve 55, and also by the sliding friction between the lower conical end of the sleeve E5 and the conical seat on the flange the amount of this friction being determined by the pressure of the spring 68 which is subject to regulation.

Lubrication of the bearing 52 is effected by movement of oil upwardly on the rotating blade as previously described; and the surfaces of the step bearing 53 are lubricated by oil passing thereto by way of the slot 63 and port 64.

The theoretical and actual advantages of the assembly are substantially the same as those described in connection with the preceding embodiments. It will be noted that in this embodiment, as in the others, actuation of the spring tensioned frictional damping means occurs only in response to an initial predetermined radial displacement of the blade-embracing sleeve, and that during this initial displacement the blade is under the damping iniluence of the oil or other liquid damping medium in the spindle base or casing.

We claim:

1. In a spinning spindle, a casing, a blade in said casing, an upper anti-friction bearing for the blade forming a fulcrum in the casing about which the lower end of the blade may oscillate in the casing, the said lower end of the blade having freedom ior such oscillation, a lower antifriction bearing for the lower end of the blade, means for mounting said lower bearing for movement in the casing with the blade in directions transverse to the longitudinal axis of said blade, said means including a iloating member or" annular cross-section irictionally engaging an end face oi the lower bearing, and resilient means for maintaining said frictional engagement, the clearance radially between the said lower bearing and the wall of the casing being greater than the clearance between the floating member and the casing so as to afford opportunity for relative movements between the member and the lower bearing in the said transverse direction.

2. A spinning spindle according to claim 1 including means tending to retain the floating member and the lower bearing in a normal coaxial relation.

S. A spinning spindle according to claim l wherein the lower bearing comprises an outer race ring and wherein further the engagement between the said floating member and the lower bearing is through said ring.

4. A spinning spindle according to claim 3 wherein the meeting surfaces of the said member and bearing are shaped as complementary cones having their apices in the axes of said member and said bearing respectively.

5. In a spinning spindle, a casing, a blade in said casing, an upper anti-friction bearing for the blade forming a ulcrum in the casing about which the lower end of the blade may oscillate in the casing, the said lower end of the blade having freedom for such oscillation, a lower antifriction bearing for the lower end of the blade, said lower bearing having an cuter race ring and including an element seated on an end of and radially interlocked with the outer race ring, means for mounting said lower bearing for movement in the casing with the blade in directions transverse to the longitudinal axis of the blade, said mounting including a iloating member of annular cross-section frictionally engaging said element, and resilient means for maintaining said frictional engagement, the clearance radially between the said lower bearing and the wall of the casing being greater than the clearance between the oating member and the casing so as to afford opportunity for relative movements between the member and the lower bearing in the said transverse direction.

6. A spinning spindle according to claim 5 wherein the said element has a'flange forengagement* with the inner surface of the race ring to effect said radial interlock.

'7. In a spinning spindle, a casing,.aj blade in said casing, an upper anti-friction bearing for the blade forming a fulcrum in the casing about which the lower end of the blade may oscillate in the casing, the said `lower end 'of the `blade having freedom for such oscillation, a lower antifriction bearing for the lower end of the blade, means for mounting said lower bearing for movement in the casing with the blade in directions transverse to the longitudinal axis of the blade, said means including a floating member of annular cross-section frictionally engaging an end face of the lower bearing, resilient means for maintaining `said frictional engagement, a second floating member of annularcross-section frictionally engaging an opposite end face of the lower bearing, and a second resilient means for maintaining the last named lfrictional engagement, the clearance radially between the said lower bearing and the wall of the casing being greater than the clearance between the said floating members and the casing so as to aiTord opportunity for relative movements between said floating members and the lower bearing in the said transverse direction.

8. A spinning spindle according to claim 7 wherein both of the bearings comprise inner and outer races and the said inner races are secured to the blade.

9. A spinning spindle according to claim 8 wherein the said resilient means exert pressure upon the opposite end faces of the outer race of the lower bearing.

10. A spinning spindle according to claim 9 wherein at least a portion of the downwardly directed axial load of the blade is supported by the resilient means at the under side of the bearing.

11. A spinning spindle according to claim 7 wherein the downward pressure of the upper resilient means slightly exceeds that of the lower resilient means.

12. A spinning spindle according to claim 7 wherein the upward pressure of the lower resilient means exceeds the downward pressure of the upper resilient means plus the weight of the blade and its attachments.

13. A spinning spindle according to claim l wherein the floating member is in the form of a sleeve of substantial length.

14. A spinning spindle according to claim 1 wherein the casing contains a viscous liquid.

15. In a spinning spindle, a fluid retaining casing, a blade in said casing, an upper anti-friction bearing for the blade forming a fulcrum in the casing about which the lower end of the blade may cscillate in the casing, the lower end of the blade having freedom for such oscillation, a lower anti-friction bearing for the lower end of the blade, said bearing having freedom for movement radially in the casing with the lower end of the blade, a support for the lower bearing including means for frictionally damping radial displacement of the bearing, an inner sleeve embracing the blade and movable with the bearing, an outer sleeve embracing and spaced from the inner sleeve and from the wall of said casing and movable with and also with respect to the bearing, said outer sleeve projecting radially beyond the bearing so as to contact the wall of the casing in advance of the bearing when the latter is displaced radially whereby continued displacement of the. bearingwill result in radial displacement of the inner sleeve with respect to the outer sleeve.

16. A spinning spindle according to claim 15 wherein the outer sleeve is vcarried by the bearing and .whereby relative movements vbetween the bearing and sleeve are dampened frictionally.

17. A spinning `spindle according to claim 15 wherein the spaces between the cuter sleeve and the wall of thecasingand between the sleeves contain a viscousl liquid displacement of which dampens the movements of the sleeves .in the casing.

18. A spinning spindle ,according to claim l5 wherein the lower bearingsupport and the outer sleeves-are resiliently urged by springs toward the bottom and top vof the: bearing respectively.

19.,A spinning spindle according to claim 18 wherein vthe spring of-the. outer sleeve is confined between theupper endof the outer sleeve and a radial'flange on the, inner sleeve .and supportsthe latter. y

2G. A spinning spindle according to claim 15 wherein the lower bearing support includes a washer having a conical recess at the top, an annular element engaged and movable with the bearing, and having a conical lower surface seated in the washer recess, and a spring supporting the washer, and wherein further a second annular element engages the upper end of and is movable with the bearing and has an upper conical surface forming an outwardly inclined seat for the lower end of the upper sleeve, and a spring is provided at the top of the sleeve reacting with the casing to urge the sleeve downwardly upon said second annular element.

2l. In a spinning spindle, a uid retaining casing, a blade in said casing and having a normal position coaxial with the latter, an upper bearing for the blade forming a fulcrum in the casing about which the lower end of the blade may oscillate in the casing, the lower end of the blade having freedom for such oscillation, a lower bearing for the lower end of the blade, said bearing having freedom for movement radially in the casing with the lower end of the blade, a support for the lower bearing including a blade-embracing sleeve also radially movable in the casing, uid means intermediate the sleeve and the wall of the casing for damping the radial motions of the blade and sleeve, spring-tensioned frictional means separate from said sleeve for damping the said radial motions of the blade, and means responsive to a radial displacement of the said sleeve and operative only after a predetermined departture of the blade from the said coaxial position for actuating said frictional damping means.

22. A spinning spindle according to claim 2l wherein the said blade embracing sleeve is suspended at its upper end in proximity to the upper bearing.

23. A spinning spindle according to claim 2l wherein the upper bearing is of roller type and has sufficient inherent looseness to permit limited oscillatory motion of the blade about the bearing as a fulcrum.

24. A spinning spindle according to claim 21 wherein the lower bearing is of tapered step type.

25. In a spinning spindle, a fluid retaining casing, a blade in said casing, an upper bearing for the blade forming a 'fulcrum in the casing about which the lower end of the blade may oscillate in the casing, the lower end of the blade having freedom for such oscillation, a blade-embracing sleeve, a bearing for the lower end of the blade carried at the lower end of said sleeve, said sleeve being suspended in the casing for radial movement with the lower end of the blade and with the lower bearing, spring-tensioned frictional means for damping the said radial motions of the blade, said damping means including a second sleeve embracing and normally spaced from the sleeve rst named and from the wall of the casing and slidably seated for radial displacement on the casing, and a spring in the casing for pressing the said second sleeve on said seat.

26. In a spinning spindle, a iiuid retaining casing, a blade in said casing having a normal position coaxial with the latter, an upper bearing for the blade forming a fulcrum in the casing about'l which the lower end of the blade may oscillate in the casing, the lower end of the blade having freedom for such oscillation, a lower bearing for the lower end of the blade, said bearing having freedom for movement radially in the casing with the lower end of the blade, a support; for the lower bearing including a blade-embracing sleeve also radially movable in the casing, fluid means intermediate the sleeve and the wall of the casing for damping the radial motions of the blade and sleeve, spring-tensioned friction means supported by and on the lower end of the casing for damping the said radial motions of the blade, and means responsive to a radial displacement of the said sleeve and operative only after a predetermined departure of the blade from the said coaxial position for actuating said frictional damping means.

References Cited in the i-lle of this patent UNITED STATES PATENTS Number Name Date 2,283,963 Winslow May 26, 1942` 2,486,296 Laird Oct. 25, 1949 2,514,157 Hilton July 4, 1950 FOREIGN PATENTS Number Country Date 701,397 Germany Jan. 15, 1941 

